Telephone system.



H. P. CLAUSEN & 0. L. GOODRUM TELEPHONE SYSTEM.

APPLICATION FILED OCT. 6. 1916 1,287,88G, Patented Dec. 17, 1918.

2 SHEETS-SHEET 1. I

Myer/for: Henry/. Clause/1. Char/e5 L. Good/Wm.

Affy H. P. CLAUSEN & C. L. GOODRUM.

IELEPHONE SYSTEM.

APPLICATION FILED OCT. 6. I916.

v.i H W w Wm 0M M mm .Dm W MP n y m V a H D1 8 Chm lea L. Good/um Cit HENRY P. CLAUSEN, OF EEOUNT VERNON, AND CHARLES E. GOODRUM, 03F BROOKLYN, NEW YORK, ASSIG-NOl-"LS TO WESTERN ELECTRIC COMFAN'Y, INCORPORATED, OF NEW YORK, El. 1 A COBPORATIGN OF KEV] YORK.

TELEPHONE SYSTEM.

Application filed Gctober 1916.

To all whom it may concern:

Be it known that we. l-lnxur l. CLAY and CHARLES L. Goooenn. citizens of the United States, residing atlilount Vernon. in the county of llestchester and State oi New York, and at Brooklyn. in the county of Kings and State of New York. respectively, have invented certain new and useful Improvements in Telephone Systems. oi which the following is a full. clear. concise. and exact description.

This invention relates to telephone s}'- ems, and especially to means for preventing wrong connections'by reason of false i1npulses caused by the careless manipulation of the calling substation apparatus.

It has been found in practice that the calling subscriber. by carelessly removing his receiver from the switchhook, interrupts the line circuitin a manner similar to the interruptions of the dial switch. It Yff8 quently results that one or more impulses may thus be transmitted to the first selector switch. thereby operating the switch so that,

it is not in the proper position to receive the first series of directive impulses. It the directii 'e impulses of the dial switch are trans mitted following .such false impulses. a wrong connection will be established.

t is the object of this invention to provide means to prevent such false impulses from misplacing an automatic switch.

One feature of this invention is the use of electrical means to restore an automatic switch it it has been misplaced. as above described.

Another feature of this invention is the provision of mechanical means to restore the switch to normal position if it has been misplaced.

Other features of this invention ill {in pear from the detailed description and claims.

Referring to the drawings. Figure 1 represents diagrammatically a portion of a tele phone system employing the present invention. The portion of the diagram included within the dotted rectangle represents the apparatus individual to the subscribers lines. At the right of the drawing there is indicated a first selector and its operating circuit.

Fig. 2 is a perspective view of a portion of a selector or numerical switch employing Specification of Letters Patent.

Patented Dec. 1?, 19118.

Serial no. 124,073.

means for restoring the switch it itis misplaced. Certain mechanical parts and the operating circuits have been omitted tron:v

such that upon their operation. they will connect the calling line to an idle trunk.

When the subscriber at substation A removes his receiver from its switchhook. line relay 1 is energized over a circuit which may be traced from grounded battery, back contact and left-hand armature of cut oil relay upper side of the line. through the substation apparatus. lower side of the line. back contact and right-hand armature of cutoti' relay 2. right-hand winding of line relay 1 to ground. Relay 1 is energized and attracts its armature. This completes an operating circuit for the plunger operating magnet 3. which circuitv may be traced from grounded battery. right-hand winding of magnet 3, front contact and armature of relay 1 to ground. Magnet 3 is energized and its plunger 4 forces the switch springs 5 into engagement with the terminals of an idle trunk. This completes an energizing circuit. for the cutoff relay 2 which may be traced from grounded battery, left-hand winding of magnet relay .2. lower line 'sWit-ch spring lower side of the trunk. relay 6, back contact and armature of release magnet 9 to ground. Cutoff relay 2 operates in the Wellknown manner to disconnect the line relay 1 from the talking circuit.

Simultaneously relay 6 attracts its armatures. and places ground on the master switch contact 20 in the wellknown manner. At the outermost armature of relay 6 a break point in the release circuit is closed. This release circuit will be hereinafter described.

When the switch springs 5 are forced into engagement with the trunk terminals, stepping relay 8 or the first selector is energized over a circuit which may be traced from trunk, upper grounded battery, relay 8, side switch 20' in its first position, upper side the switch spring 5, front contact and left-hand armature or outed relay :2, upper side of the line, through the substation apparatus, lower side of the line, trout contact and right-hand armature or" cutotr relay 2, lower switch spring 5, lower side of the trunk, relay 6, back contact and arma ture of release magnet 9 to ground. Stepping relay 8 attaots its armature and closes a break-point in the energizing circuit of the slow-releasing relay 10, which circuit may be traced from grounded battery, relay 10, back contact and armature ot the test relay 11 to ground.

During the interruptions of the line circuit, caused by the operation of the dial switch sender or in response to uniformly timed impulses of current from any suitable source, stepping relayfi is intermittently deenergized and energized, and its armature thereby caused to vibrate. Relay 10, being slow to release, does not retract its armatures during the resulting momentary interruptions of energizing circuit.

At the nrst deenergization, the stepping relay 8 retracts its armature and completes energizing circuit for the second slow release relay 1 This circuit. may be traced from grounded battery, relay 12, front contact and left-hand armature of relay 10, back contact and armature of stepping relay 8, back contact and armature or" relay .11 to ground. Eelay 12 attracts its armature and completes an operating circuit for escape magnet 13, which circuitmay be traced from grounded battery, escape magnet 13, front contact and armature of relay 1-2 to ground. An operating circuit for the primary magnet PM, in parallel with the enerc'izin circuit or" relay 12 extends iroin c k" l T grounded battery, primary magnet "front -contact and left "and armature of relay 10, back contact and armature of relay 8, back contact and armature of test relay 11 to ground.

In response to impulses from the dial switch the primary magnet PM operates the switch the prescribed. number of stops, corresponding to the first digit of the desired number. At the close of the first series of impulses, stepping relay 8 attracts its armature for a relatively long interval and thereby interrupts at its back contact the energi'zing circuit for the slow releasing relay l2.

Relay 12 retracts-its armature and breaks the operating circuit for the escape magnet 13. The escape magnet, on its dee'nergization, moves the side switch wipers into their second position.

operating now completed, wh'cu from grounded butte circuit for th= secondary circuit e secondary magnet perates to cause the switch brushes 22 and 23 to traverse the terminals 2e and 25 of the trunks terminating in the bank. The terminals of the busy trunks traversed by the lower switch brush 23 are provided with raised potential so that thetest relay 11 will not be energized. When, however, the switch brushes engage the terminals of an idle trunk, relay 11 will pull up, interrupting the circuit for the stepping magnet 15. The energization of test relay 11 6011117131153 an energizing circuit for the escape magnet which extends from ground, armature and front contact of relay 11, front contact and right-hand armature of relay 10, escape magnet 13 to grounded bat tery. moves the side switch wipers into their third position, in a manner which is clearlydisclosed in the patent to C. L. Goodrurn No. 1,231,013, June 26, 191?.

As the operation of the switches succeeding the first selector may be of substantially the same character as that shown in the patent to C; L. Goodrum No. 1,251,503, Jan. 1, 1918, the operation of establishing the rest of the connection will not be described.

Before the side switch wipers move into their third position, the deenergizations of the stepping relay 8 are momentary in duration. Slow-releasing relay 10, therefore, re mains energized and holds open the operating circuit of the release magnet 9, which circuit may be traced from grounded battery, release magnet 9, outermost armature and front contact of relay 6, side switch wiper 18, back contact and lett-hand armature oi relay 10, back contactand armature of relay 8, and back contactand armature of relay 11 to ground, It the calling party should. abandon the call by interrupting the substation circuit, after series of impulses is sent, stepping relay 8 will retract its armatu e, thereby causing the deenergization or relay 10 and the com letion of the release circuit as described.

at the time the side switch moves out of position 2, and the stepping relay 8 deenergizes, the relay 11 as described is energized. ll hen, however, the side switch reaches position 3, relay 11 becomes deenergized, due to certain changes at the succeedinn selector switch, thus opening a release circuit which would otherwise be completed from ground, front contact and armature or" test relay 11, back contact and right-hand armature of relay 10, side switch wiper 18 in its third position, outermost armature and trout contact of relay 6, release magnet to 'roundf the termination of the conversation, relay 11 becomes energized, due to certain changes at the succeeding switch.

The escape magnet is energized and f menace in a manner which in be well understood from the above mentioned Patent No. 1,251,503.

Should the calling party, after the operation of the line switch, replace his receiver on the hook without operating the dial switch, the stepping relay 8 will become deenergizcd, thereby con'ipleting' a circuit for the release magnet 9. This circuit may be traced from grounded battery. release magnet S,iront contact and outermost armature ot relay 6, and back contacts and armatures ct relays 10, S and ll to ground. as previv d scribed. The operation or release 9 interrupts the circuit of relays 6 z and magnet l t the switch has i 1 its normal position, release ablishes a holding circuit for itself, which extends from grounded bat tcrv, magnet o normal con-tact 1?, front itact and re of relay 5 to ground.

The deenerg zation of magnet 3 allows the pint er l to be retracted. The armatnres of cutolt' relay 2 are retracted and connect the subscribefis line to his line relay 1. The retraction oi the armatures of relay 6 removes the busy potential from the bank contact of the master controll r, thus permitting the trunk to again be selected.

"1 the preceding description it is assumed t the calling party did not send any false impulses by the careless removal of his receiver from the switchhook.

.ssuming now that the subscriber raises his receiver and then allows it to drop back on the switchhoolt l efore he finally removes it for use, the (prick-operating line switch will connect the calling substation to an idle trunk. and when the receiver falls back on the switehhook. an impu se similar to those transmitted by the dial switch will operate the selector switch one step forward in a manner previously described. If the calling party now sends impulses corresponding to the first digitof the desired line, the switch will be wrone'l v' positioned, and a wrong connection will result.

The purpose of the present invention is to avoid the misplacement of the switch, by reason of false impulses caused by the careless remova' of the receiver. In this arrangement. if a single impulse is sent, followed by a time interval of sufficient length to permit the sidev switch to move into position 2, the switch will then proceed to hunt tor an idle trunk in the well-known manner. llhen the switch has taken a single primary step. and proceeds in its hunting operation, an oft-normal contact 19 will be closed to lid ground. thereby completing a release cir cuit which may be traced from grounded battery. release magnet 9, oil-normal con act 19 to ground. This will restore the first selector switch to normal position, whereupon it will be in condition to receive the impulses from the dial switch. F or con-- venience in description, it has been assumed that the apparatus will be designed to intercept one false impulse. It will be understood, however, that the apparatus may be arranged to intercept two or more false impulses by properly positioning the oil-normal contact 19.

Referring to Fig. 2, the selector switch brush shaft mounted for rotary movement in a supporting structure. (not shown). This shaft carries brushes 51., which engage the passive contacts of a switch bank 5:2. brushes 51 are so positioned with respect. to the passive contacts with which they cooperate, that it is necessary for the brushes to be elevated two vertical steps before they are in operative relation to the first group of terminals of the switch bank. lVhen, however, this switch is employed in the system such as that shown in Fig. 2. it will be understood that only two of the brushes 51 and their corresponding contacts will be necessary. The shaft at its intermediate portion is provided with vertical ratchet teeth which are adapted to be engaged by the vertical pawl 54:, carried by a pivoted arm controlled by the armature of motor magnet The shaft is also provided with rotary ratchet teeth 56, which are adapted to be engaged by the rotary pawl 57. This pawl is also carried by a pivoted arm which is controlled by the armature of the rotary magnet 58.

59 designates a frame which is pivoted on the vertical rod 60. This frame is provided with a vertical holding dog 51, and a rotary holding dog 62. The frame 59 is also provided with an angular extension 68, the purpose of which will be hereinafter described. The frame 59 is secured to the armature of the release magnet 65, and it will be understood that when the release magnet 65 is ener ized. the holding dogs 61 and 62 will be disengaged from the vertical and rotary ratchet teeth. allowing the shaft to be restored to its normal position.

The shaft 50 carries a pin 64 which is adapted to engage the angular extension (33 when the shaft is elevated a prescribed number of steps, and then proceeds in its limit ing operation.

Referring to the operation of the switch, when the directive impulses of the dial The operate said switch, and :means for rendering said switch selectively non-responsive to a single impulse of current.

12. In an automatic telephone system, the combination of an impulse transmitter, an impulseresponding device, and means responsive to the operation of said device for automatically re-setting the device when only one impulse is received by it. 4

13. In a telephone system, the combination With a telephone line extending from substation apparatus to main station apparatus, a circuit interrupter and a switch for the said substation apparatus, a step-by-step switch and a source of current at the main station, means to cause the said step-by-step switch to be operated by the said source of current under the control of the said circuit interrupter, means to cause the said substation switch to make less than a predetermined number of line circuit interruptions, means to cause said circuit interrupter to make more than the predetermined number of line circuit interruptions, and correcting apparatus for the sad step-by-step switch at the main station for restoring the said switch to normal after being actuated under the control of the said switch making less than the predetermined number of circuit interruptions, whereby a subsequent operation of the said circuit interrupter to make more than the predetermined number of circuit interruptions Will move the said switch to the same position that the said switch would be moved were the said switch first moved under the control of the said circuit interrupter with the same actuation of the said circuit interrupter.

14. In an automatic telephone system, the combination with a plurality of telephone lines having numerical designations, for calling purposes, a selective switch mechanism at a line interconnecting station under the control of the line apparatus of the lines adapted to interconnect the said lines, substation means for each of the lines for pro ducing circuit interruptions or the said lines to control the said selective switch mechanism, whereby the said selective switch mech anism may operate to connect calling and called telephone lines, and controlling apparatus for the said selective switch mechanism at the line interconnecting station to restore the said selective switch mechanism to normal position after having been moved under the control or" less than a predetermined number of line circuit interruptions.

In Witness whereof, we hereunto subscribe our names this lth day of October, A. D.

HENRY P. CLAUSEN. CHARLES L. GOODRUM.

@opies of this patent may he obtained for five cents each, by addressing the Commissioner of Eatcnts, Washington, D. G. 

